For decades the semi-wild ponies found roaming across some of Britain's most beautiful moorland have been identified by the branding on their flanks made with red-hot irons. The practice involves the application of very hot metal to the skin for several seconds until the hide turns a light tan colour.

But now the use of irons is on the way out, following a sustained campaign by animal welfare organisations that claim the practice harms the horses. The British Veterinary Association, which supports a ban, has noted that "hot branding is generally carried out without analgesia and is undoubtedly a painful process".

Moorland pony societies have agreed a code of practice on hot branding and have agreed to use the method of identification only when strictly necessary. The move follows a decision to ban the use of branding in Scotland and is seen as the beginning of the end for hot branding of moorland ponies.

An independent report in 2010 commissioned by the RSPCA concluded that the practice was "likely to cause significant pain and suffering". It recommended that horse-owners use microchips to identify their animals. Alternatively, they should consider freeze-marking – the use of a cold branding iron held on the skin to destroy the hair follicles and make a bald mark.

Microchipping is a legal requirement for all horses and ponies born after 1 July 2009. However, the thousands of ponies on England's moors are exempt. Although wild, they are used for grazing, so their owners need to identify them. Some moorland ponies are branded as many as five times.

Roly Owers, chief executive of World Horse Welfare, welcomed moves to phase out the use of hot branding. "There is no doubt it is painful," Owers said.